The Search for the Genetic Material
by Heiri-XQR
Summary: Prompt was the title. A bit of Johnkat in which John overhears Rose and Kanaya talking and goes to Karkat for answers. Results in lemon goodness.


A/N: In my genetics lecture a friend simply gave me a title. This is the result. I'm sure I need not warn you there will be tentabulges, nooks and genetic material.

**The Search for the Genetic Material**

"Hey, Karkat!" John pounced on the troll who sat at his husktop.

"Fuck, John!" he exclaimed, startled. He gave the human no attention, looked at the jumble of letters that had appeared on his screen and pressed the backspace button which more force than necessary. "Can't you see I'm busy?" he asked when he realised that John had no intention of releasing his neck so soon.

John peered forward, leaning his head on Karkat's shoulder. "Who're you talking to? Gamzee?"

"Yes, John, congratulations on your observation skills. Now, what the fuck do you want?"

"Oh, if you're busy it can wait."

Karkat sighed and removed John's arms from himself, spinning around in the chair to face the human. "No. You've already bothered the shit out of me, so tell me why you're here."

John smiled; he liked being able to bother the troll like this. "Oh – Gamzee's pestering you."

"He and his 'sick fires' he learnt from Strider can wait. I need a break from that shit and to get you to fuck off."

John's smile widened; there wasn't much that people could do to make Karkat ignore his moirail.

"Fuck me – will you stop with that creepy smile. Gog."

"Okay, well I have a question – and it may be kind of personal, but I overheard Rose and Kanaya talking and it sounded really interesting, so I figured -"

"JOHN. Get to the fucking point."

"What colour is your genetic material?"

Karkat's eyes widened, his face filling with colour. "WHAT THE FUCK KIND OF QUESTION IS THAT? IF YOU HADN'T REALISED THIS CAN BE A SENSITIVE SUBJECT FOR SOME OF US, YOU IGNORANT LITTLE SHIT. WHY THE FUCK DID YOU EVEN ASK IT THAT WAY? SURE, ASK SOMEONE FOR THEIR BLOOD COLOUR AND THEY'LL PROBABLY GIVE YOUR NOSY ASS AN ANSWER, BUT ASKING ABOUT THAT? FUCKING HELL, EGBERT. WHY?"

John scratched the back of his head and gave an 'I'm sorry' smile. "Sorry, Karkat, I didn't mean to…um, get all up in your 'nook'?"

Karkat threw his hands in the hair. "JUST STOP. I KNOW YOU'RE TRYING TO BE FUCKING CULTURAL, BUT I CAN'T DEAL WITH THAT. OH SHIT – ARE YOU TRYING TO COME ON TO ME RIGHT NOW? BECAUSE THAT'S A SHITTY WAY OF DOING IT."

The boy took a step forward and hugged the troll who was now on his feet.

"YOU FUCKING ARE, YOU PIECE OF SHIT."

"No, this is just me trying to calm you down." He placed a hand on Karkat's cheek and papped gently.

"OH MY FUCKING GOG. LET GO OF ME, YOU NOOKSTAIN. I CAN'T BE CHEATING ON GAMZEE WITH A FUCKASS LIKE YOU." The troll pushed the boy away, holding him at arm's length.

"Aw, I've made a real mess of this," John sighed. "I'll just go and ask Kanaya or -"

"DON'T YOU FUCKING DARE. SIT." John looked around for something to sit on, eventually deciding on the floor. Karkat sat back down, quickly typed something to Gamzee and then spun round to face him. "THERE'S NO WAY I CAN ALLOW YOU TO GO RUNNING ROUND LIKE AN IGNORANT SHITSPONGE, SO I AM GOING TO TELL YOU SOMETHING WHICH YOU CAN SHARE WITH THAT RAPPING SUNGLASSES-WEARING BULGE SUCKER YOU CALL A FRIEND."

"Karkat, you don't have to yell, I'm right here."

"YOU THINK YOU DESERVE NOT TO BE FUCKING YELLED AT UNTIL YOUR HEAR DUCTS CAN NO LONGER PROCESS MY VOICE? NO, I DON'T THINK YOU'VE EARNED THAT PRIVILEDGE YET. SO. THE FIRST THING YOU NEED TO PUT IN YOUR THINK PAN AND REMEMBER IS THAT ALL THE FLUIDS IN OUR BODIES ARE THE SAME FUCKING COLOUR. ALL OF THEM. SO DON'T GO ROUND ASKING FOR SOME PERSONAL SHIT LIKE GENETIC MATERIAL WHEN YOU COULD ASK ABOUT BLOOD. SECOND: SOME OF US DON'T WANT TO DISCLOSE THAT KIND OF INFORMATION."

"Karkat, everyone knows that your blood is red."

"THAT STILL DOESN'T MAKE IT OKAY TO FLAUNT IT AROUND. I'M A FUCKING MUTANT, JOHN. IF THE CONDESCE FOUND OUT I WOULD BE FUCKING CULLED. I ASSUME YOUR TINY THINK PAN UNDERSTANDS WHAT THE MEANS?"

"I know; they'd kill you. Anyway, thanks for answering my question." He smiled and began to get up.

"I'M NOT FUCKING DONE WITH YOU. IF WE'RE GOING TO DO THIS, WE'RE GOING TO DO THIS PROPERLY. I CAN'T HAVE YOU GOING ROUND PAPPING WHOEVER YOU WANT WITH NO FUCKING COSIDERATION FOR WHETHER THEIR QUADRANT IS FILLED OR NOT."

"I just thought that's what I should do to calm -"

"OH. YOU JUST THOUGHT? YOU THOUGHT FUCKING WRONG. DO YOU LOOK LIKE MY MOIRAIL? DO I LOOK LIKE I DON'T HAVE ONE ALREADY?"

"No…but we…" John looked up into Karkat's eyes, trying to convey the rest of his sentence.

"WE'RE NOT EVEN MATESPRITS, YOU STUPID SHIT."

"We aren't?"

"GOG, JOHN. I KNOW I'M FUCKING RED FOR YOU, BUT YOU SAID YOU WERE THAT STUPID HUMAN THING THAT MEANS YOU COULDN'T BE WITH ME – HOMOSEXUAL?"

"People can change…" He pushed his fingers together. "Besides, what about all the hugs and stuff…"

"ISN'T THAT ONE OF YOUR STUPID EARTH CUSTOMS? HARLEY DOES IT ALL THE FUCKING TIME TO EVERYONE."

"Jade's just being friendly, but when I hug people it means they're special…"

Karkat was momentarily speechless. "YOU WINDSOCK HEADED SHITBAG. WAS THAT A FUCKING DECLARATION OF FLUSHED FEELINGS THAT YOU CLAIMED YOU COULDN'T HAVE? DO YOU EVEN KNOW HOW INSANE IT DROVE ME EVERY TIME YOU DID THAT? I HAD TO TRAIN MYSELF TO LEAVE YOU ALONE AND NOT SEE EVERY IMPLICATION IN EVERY ACTION YOU WERE SUGGESTING WAS JUST THAT HUMAN EMOTION CALLED FRIENDSHIP. I FUCKING MOVED ON WITH LIFE AND CAST THOSE FEELINGS INTO THE DEEPEST OCEAN OF NEVER FUCKING HAPPENING IN THIS SHITTY UNIVERSE. AND NOW YOU'RE TELLING ME THAT YOU ACTUALLY MEANT IT TO LOOK THE WAY IT LOOKED. YOU'RE A FUCKING MASTERPIECE, EGBERT. YOUR LITTLE PRANK HAS GONE QUITE FAR ENOUGH, SO WHY DON'T YOU JUST TAKE YOUR SHITTY -"

Karkat was cut off by John pressing his lips against his own. The moment they broke the troll opened his mouth to continue his lecture, but John just pressed a finger to his lips.

"Now, listen. When we first had that conversation many moons ago you were looking for a black relationship and I never wanted that. So, I have been trying to see how you'd respond to a red one, but you never really showed any signs, so I didn't want to just come out and ask – well I did…I just didn't find the right time. But seeing as you didn't seem to mind the hugs I thought I'd just continue… I'm glad you feel the same way though…"

John was pulled roughly into Karkat's lap and then they proceeded to engage in some long overdue sloppy make outs. The troll had one arm around John's waist, the other on his neck, holding him there while he crushed his lips against the human's, not stopping until John was beating a hand against his chest. He let go and John inhaled deeply.

"That was…amazing," he said once he'd caught his breath.

Karkat let a finger twirl around a stand of John's hair. "You are the biggest shithead I've ever known…but I still love you."

John blushed and smiled at Karkat's sudden change in disposition.

"But if you ever do something so frustratingly stupid again I may have to end this beautiful matespritship. Now get the fuck out so I can talk to my moirail."

"You are so unromantic sometimes."

"Oh, but this is just the beginning." He gave John a little shove. The boy reached down and kissed his cheek before leaving the room.

-A few weeks later-

They were sat on John's bed, Karkat propped up on a pillow with John lying on his lap. Tonight Karkat had won the choice of film, choosing a human rom-com that made John groan.

"I'm not going to get cultured by just listening to your shitty summaries and horrid reviews – which aren't even accurate most of the time. My Big Fat Greek Wedding was way better than you rated it."

Tonight they were watching 50 First Dates, which was okay, but John thought it was a film that only needed watching once. Twice was too much for him, but at least he got to spend a couple of hours curled in his boyfriend's lap. The credits rolled and John turned to look up at the troll.

"Karkat…are you crying?"

"No, I'm not fucking crying."

John reached up and brushed a crimson tear away. "So you liked it?"

"Gog fucking damn. It's just so sad that she could never remember. Imagine spending every day having to relive that terrible story. I think I'd cull myself."

"Yeah, but you would only remember it for one day and then you'd forget."

The troll wiped his eyes. "That's what makes it so fucking tragic. I think that's the saddest human film I've seen. Do they get worse?"

"Oh yeah. Just wait until we watch a series of films where you get attached to the characters a lot more and then have to watch them die."

"Jegus that is evil for human standards."

"You get used to it," John said as he reached over, grabbed the remote and turned the TV off. "Was there anything you wanted to do now?"

Karkat glanced out the window. "Isn't this the part where you say you're tired and want to sleep?"

"Don't you know that in the winter the sun sets earlier? But that doesn't mean that I'll sleep earlier."

"Well excuse me for living on a planet where things don't function the same way. I was expecting to sit here watching you sleep until I was tired too, so I have no idea what to do now."

"I'm going to make some hot chocolate. Do you want some?"

"What the fuck is that?"

"A drink that tastes like chocolate." John got up, taking Karkat's hand. "I'll show you."

The kitchen was cold and Karkat was glad he was in a turtleneck. John flicked the switch on the kettle and stood with his arms hugging himself while he waited, watching as Karkat prodded the bread someone had left on the counter. The kettle made a noise and both of them whipped around, Karkat due to surprise and John to start making the hot chocolate. The troll shuffled forward, arms wrapping around John as he watched the boy put some brown coloured power into the water.

"Do you want some?"

"I'll just taste yours, because that looking fucking odd. Why would you want to drink something hot? Isn't it going to burn your mouth?"

John laughed. "You wait for it to cool, silly."

"What the fuck? Then why did you just wait for the water to boil?"

"Because you wait for it to be warm, not cold."

"Weird."

They returned upstairs and John crawled onto the bed, pulling the covers over his legs.

"I thought you said it was too early to sleep?"

"Yeah, but I'm cold."

Karkat shrugged and climbed in next to John, taking out one of the small computer devices John had given him.

"Anyone say anything?" he asked.

"No. They know I'm busy with you. But you never know when something terrible is happening and my leadership skills are needed."

"So, what kind of matesprit things do they expect we're doing?"

"Gog, John, why don't you ask them? They probably won't have an answer for you because we're not all nosy fucks like you. Do you think I sit there wondering if Sollux is in the middle of having sloppy make outs with Feferi? Wait. Are you telling me that you think about whether Rose and Kanaya are -"

"No, no, no," John said quickly. "I was just trying to get you to tell me what matesprits usually do…"

"Oh." Karkat blushed slightly. "Well, it's pretty similar to what happens in your human red rom-coms."

John took a sip of his hot chocolate, but then set it back down when he realised it was still far too hot. "But isn't there something to do with buckets?"

Karkat placed a finger to John's lips. "One day you will learn not to be so fucking blunt." The troll moved so that he was straddling John's hips, brushing his lips against the boy's. His hands slipped under the blue shirt, slowly making their way up John's smooth chest, tweaking his nipples.

"Ah – Karkat!" John broke the kiss. "What are you doing?"

"Showing you what matesprits do? Didn't you basically just ask me to do this?"

"I just…I didn't need a demonstration – ah, Karkat, they're sensitive!" John squeaked when the troll continued to rub this thumbs across the tender nubs.

"I know," he smirked, "and it's so cute to see you react like this. Besides, seeing as we _are_ matesprits I should show you how to act like one. So far it's felt more like we're pale than red." He started to push John's shirt up and the heir placed his hand's on Karkat's arms, not sure if he wanted to do this now… The troll said nothing, just gazing at John who then released his arms and let him continue to take his shirt off. "We don't have to do this now," Karkat said when he saw how unsure John looked.

John shook his head. "No, I want to…it's just kind of scary. I imagined what it would be like…what if it doesn't go how I thought it would…"

"Gog, John, you need to stop over thinking stuff. Now shut up and put your hands on my body or something." The heir slipped his hands under Karkat's jumper. "Fuck, your hands are cold."

While John's hands explored the troll's chest Karkat's hand was making its way south, palming John's very odd bulge through his trousers. John made a quiet noise and shifted to give the other better access. He grabbed the front of Karkat's jumper, pulling him down for a kiss, his hands then tangling themselves in his hair, finding the small nubby horns nestled in the black mess. He had once over heard someone say that troll horns were sensitive, now it was time to find out. Slowly, he started to stroke them from base to tip, smiling as Karkat moaned into the kiss. It wasn't long before Karkat was lying on John's chest, begging him to stop.

"But you sound like you're enjoying it."

"Ahhh, but – nng – I don't want, mmm, to finish so soon…"

John released the troll and smiled at him, watching as he roughly pulled off the jumper he was still wearing and then moved to start unbuttoning the jeans John was wearing. Gog, these things weren't easy to pull down. Karkat gave up and thrust a hand down John's pants, eyes widening when his hand brushed against something he hadn't thought would be there.

John cocked his head at the troll. "Something wrong?"

"Well, I wasn't expecting your anatomy to be the same, but the fluffiness is quite a surprise."

John smiled. "It's a sign that I'm becoming a man."

Karkat continued to grope at the thing between John's legs, feeling it becoming harder under his touch. John sat there, enjoying both the feeling and the facial expressions Karkat was making.

"Okay, what the fuck am I even touching?" The troll retracted his hand and began to pull the jeans off completely, then sat back and observed John's naked body. "That sure looks fucking weird."

"I can't wait to see what you have then."

Karkat stood on his knees and shuffled forward. "Would you like to do the honours?"

John tugged at the belt teasingly and unbuckled it, followed by the button, by which point the trousers were already halfway down the troll's grey hips. The heir pulled them down, careful not to pull his underwear off in the process. John hooked a finger under the elastic band and slowly began to unveil Karkat's most intimate area. He flinched when he felt something sticky flick against his finger. It was John's turn to stare at his partner, wide-eyed. Karkat tried not to smirk too much as the boy decided it was best to use two hands and stay away from the centre.

"Oh my God," John said rather calmly as he was faced with the red hued tentabulge, coated in some kind of slimy substance.

"We could have taken this so much slower if you hadn't played with my horns," Karkat huffed. "But I must say I was expecting you to react worse." He slipped off the bed and kicked off the trousers before climbing on top of John, starting with a kiss.

The heir squirmed as he felt the slick tentacle brush against his lower abdomen, but soon forgot about it when he felt Karkat's hand wrap around his member. The troll pumped it slowly, getting a feel for the human's anatomy. Then he let his hand wander, gently squeezing the two round things down there – John seemed to like that.

"What are they for?" Karkat asked.

"They…uh, ah – are for…reproduction."

Karkat raised an eyebrow. Humans sure were weird. He took John's hand, guiding it to his neglected appendage. It felt weird to touch, but supposed it was just like using more lube than necessary. Then he felt it coil around his hand as he began to stroke.

"Karkat, that's really, really weird."

The troll shrugged. "It's not my fault you have such a stiff thing that isn't as cool."

"It just feels like I'm getting a hand job from your bulge rather than giving it one."

"Gog, John, it's not like I can control it once it's like this." He kissed the boy. "Just try and forget about it." He began to pump a bit faster, liking the way that John's face looked and the quiet noises he was making. His other hand explored more of John, searching. "John. Do humans not have nooks?"

"Mm, Karkat, you never actually told me what that was; just occasionally called me a 'nookstain'."

The troll sighed and took John's hand again, placing it behind his bulge so that the boy could feel the opening there.

"Oh. Girls have things like that, but not guys."

Karkat refrained from commenting and moved to position himself for easy access. There was a brief glance exchanged before Karkat lowered himself onto John's member, letting out a moan as he did. He began to roll his hips and it wasn't long before John was moaning his name in an attempt to pretend he wasn't making the noises he was.

"Relax," Karkat breathed into his ear as he tweaked the heir's already hard nipples. That made John thrust his hips up and Karkat smirked. "There, now move with me." He placed John's hands on his hips and set a rhythm which John tried to follow.

Now that he had John doing more of the work he could worship John's body, kissing his jaw, neck, collarbone… Meanwhile the heir's hands had found their way back into Karkat's hair and his horns. Soon enough Karkat was reduced to the panting mess he had been earlier, his breath hot on John's neck.

"J-John, where's – ah – the bucket?"

"Mmm? I don't have one."

"Fuck, nnng, I saw you with one."

It was hard to concentrate on anything right now, but a memory was coming back to him and he laughed. "In the kitchen – ah, I'm so close…"

Karkat wormed his way out of John's grip. "Why the fuck…is it there?"

"It's my dad's."

The look on Karkat's face told John that that was not a good answer. "WHAT KIND OF SICK FUCKS ARE YOU TWO?"

John pulled Karkat back down by the shoulders. "It's not what you think, I'll mmm explain later. Come on, let's enjoy this." He slid a finger down a horn, barely making contact.

Karkat shivered. "Fucking huma –ah."

John's free hand was stroking his bulge again. It was all too much…

"Karkat, I'm gonna…" He just assumed that Karkat would catch his drift as he released inside the troll who was far too busy being stimulated in all the best places.

Karkat let out a loud groan and John felt his groin and legs become wet with who knew what. The troll rolled off of him, lying panting by his side, too hot to want to be in contact with him any longer. John looked down at his lap to find himself covered in a red coloured liquid, like diluted blood, mixed with his own fluids. He touched a bit with his finger – slightly sticky – and then contemplated tasting it, but deciding he wasn't feeling that adventurous today. He felt Karkat interlace his fingers with his free hand.

"Is this it?" John asked.

"Is what it? I thought you enjoyed it?"

John shook his head and motioned to the mess. "Is that your genetic material?"

"No shit. And before you complain – it's your fault."

"There's so much…" John said, more to himself than Karkat.

"Why do you think I asked you where your bucket was? Could have saved a lot of mess, not that you made much anyway."

"Humans only make a little bit, so we don't use buckets at all."

"Fucking. Weird. If I wasn't already so turned on I probably would have walked out when you mentioned sharing."

"I think we both still have a lot to learn about each others' cultures."

"Oh what joy that's going to be," Karkat said, trying not to sound as sarcastic as he usually did.

"But at least I've found the genetic material now." John grinned.

A/N: So shoot me for a shitty end. But that's what I was here to do and I did it. So woo. Enjoy yo' smut.


End file.
